Tokuyama Corporation

Tohoku University

Nagoya University

Tokuyams Corporation

Kentaro Fukuda

Noriaki Kawaguchi

Akira Yoshikawa

Takayuki Yanagida

Yui Yokota

Sumito Ishizu

Yutaka Fujimoto

Kenji Fukunaga

Kenichi Watanabe

Tetsuo Iguchi

Hiroya Yamashita

Toshihisa Suyama

Atsushi Yamazaki

Akira Uritani

Hiroaki Saito

Hisanori Yamane

Tetsuya Kawano

Yoshihiko Takahashi

Yuya Kawabata

Hirokatsu Hayashi

Takahiro Yoshida

The present invention aims at providing a scintillator for high temperature environments which has satisfactory light emission characteristics under high temperature environments; and a method for measuring radiation under high temperature environments. The scintillator for high temperature environments comprises a colquiriite-type crystal represented by the chemical formula LiMMX(where Mis at least one alkaline earth metal element selected from Mg, Ca, Sr and Ba, Mis at least one metal element selected from Al, Ga and Sc, and X is at least one halogen element selected from F, Cl, Br and I), for example, typified by LiCaAlF, and the crystal optionally containing a lanthanoid element such as Ce or Eu. The method for measuring radiation under high temperature environments uses the scintillator.

Scintillator, radiation detector, and method for detecting radiation

A neutron scintillator is formed of a resin-based composite. The resin-based composite includes a phosphor part (A) formed of a resin composition including inorganic phosphor particles containing at least one kind of neutron-capturing isotope that is selected from lithium 6 and boron 10 such as Eu:LiCaAlFand a resin, and at least one wavelength converting part (B) comprising a wavelength converting fiber or a wavelength converting sheet. In the neutron scintillator, it is preferred that the wavelength converting part (B) is enclosed in the phosphor part (A).

Neutron scintillator, neutron detector and method for manufacturing neutron scintillator

A neutron scintillator excellent in neutron detection efficiency and n/&#x3b3; discrimination ability, having uniform characteristics, and easily available in a large size is provided. The neutron scintillator comprises a resin composition having eutectic particles incorporated in a resin having a similar refractive index, the eutectic particles having a sphere equivalent diameter of the order of 50 to 1000 &#x3bc;m and being composed of lithium fluoride and an inorganic fluorescent material, such as MgF, CaFor SrF, the inorganic fluorescent material containing a lanthanoid, such as Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm or Yb, as a luminescent center atom.

Neutron scintillator and neutron detector

A neutron scintillator composed of a resin composition comprising (A) an inorganic phosphor containing at least one neutron capture isotope selected from lithium 6 and boron 10 and (B) a resin, wherein

Neutron scintillator, neutron detection method and neutron detector

A neutron scintillator includes a resin composition having a resin and an inorganic phosphor containing at least one kind of neutron-capturing isotope that is selected from lithium 6 and boron 10 such as Eu:LiCaAlF. The resin composition contains 0.2-30&#xd7;10atom/mmof lithium 6 and 0.05-8&#xd7;10atom/mmof boron 10 and is in such a form that the average diameter of inscribed spheres is 5 mm or less. A neutron scintillator is formed of a resin-based composite having a plurality of parts formed of the aforesaid resin composition and supplementing part(s), in which the content of the neutron-capturing isotope is not more than &#xbd; of the content of the neutron-capturing isotope in the resin composition. The ratio of the distance between the centers of inscribed spheres in the individual parts formed of the resin composition to the sum of the diameters of the inscribed spheres therein is 1.2 or greater.

A light emitting element according to one embodiment of the present invention is configured of a metal fluoride crystal which is represented by chemical formula LiM1M2F6 (wherein Li includes 6Li; M1 represents at least one alkaline earth metal element selected from among Mg, Ca, Sr and Ba; and M2 represents at least one metal element selected from among Al, Ga and Sc), said metal fluoride crystal containing 0.02% by mole or more of Eu and having an Eu2+ concentration of less than 0.01% by mole.

Metal fluoride crystal, light emitting element, scintillator, method of detecting neutron, and method of producing metal fluoride crystal

[Problems to be Solved] A neutron scintillator excellent in detection efficiency for neutrons, an S/N ratio, and n/&#x3b3; discrimination ability, and a eutectic preferred for the neutron scintillator are provided. [Means to Solve the Problems] A metal fluoride eutectic, in which a lithium fluoride crystal phase and a crystal phase represented by the chemical formula CaSrF(where x denotes a number greater than 0, but not larger than 1), such as SrFor CaSrF, are present in a phase-separated state; a neutron scintillator comprising the eutectic; and a neutron imaging device comprising a combination of the neutron scintillator and a position-sensitive photomultiplier tube.

Metal fluoride eutectic, neutron scintillator and neutron imaging device

Provided is a scintillation neutron detector capable of measuring neutrons with precision even under a high amount of &#x3b3; rays as background noise and excellent in neutron counting precision, the scintillation neutron detector comprising a neutron scintillator crystal containingLi, and the crystal having a specific surface area of no less than 60 cm/cm.

Neutron detector

[Problems to be Solved] A colquiriite-type crystal preferred for a scintillator for neutron detection, which has high sensitivity to neutron and which is reduced in background noise attributed to &#x3b3; rays; a scintillator for neutron detection which comprises this crystal; and a neutron detector are provided. [Means to Solve the Problems] A colquiriite-type crystal represented by the chemical formula LiMMX, such as LiCaAlF, containing Na and Ce, for example, the colquiriite-type crystal containing at least one alkali metal element selected from the group consisting of Na, K, Rb and Cs, and a lanthanoid element selected from the group consisting of Ce, Pr and Nd, and having an isotopic ratio ofLi of 20 mol % or more, preferably 50 mol % or more; a scintillator for neutron detection comprising the colquiriite-type crystal; and a neutron detector.

Colquiriite-type crystal, scintillator for neutron detection and neutron detector

Provided is a scintillator for neutrons that allows the detection of neutrons with superb sensitivity and that is little affected by background noise derived from &#x3b3;-rays, and a neutron detector that uses the neutron scintillator. The scintillator for neutrons comprises borate that contains at least Mg and a divalent transition element.

Scintillator for neutrons and neutron detector

[Problems to be Solved] A neutron scintillator excellent in neutron detection efficiency and n/&#x3b3; discrimination ability, and a metal fluoride eutectic preferred for the neutron scintillator are provided. [Means to Solve the Problems] A metal fluoride eutectic having a cerium-containing calcium fluoride crystal phase and a lithium fluoride crystal phase present in a phase-separated state, and a neutron scintillator comprising the metal fluoride eutectic.

Metal fluoride eutectic and neutron scintillator

Provided is a radiation detector with improved n/&#x3b3; discrimination and usable even under high counting rate conditions with a reduced load on a signal-processing system. The detector capable of distinguishing neutron and gamma-ray events includes: a scintillator; an optical filter; a first photodetector to which a first part of light emitted from the scintillator is introduced via the optical filter; and a second photodetector to which a second part of light emitted from the scintillator is introduced not via the optical filter, wherein, for a set of two wavelengths A and (A+B) nm, the scintillator emits at least a light of A nm and a light of (A+B) nm when irradiated by gamma-ray, and emits a light of A nm and does not emit a light of (A+B) nm when irradiated by neutrons; and the optical filter blocks the light of A nm and transmits the light of (A+B) nm.

Radiation detector

[Problems to be Solved] A neutron scintillator excellent in neutron detection efficiency and n/&#x3b3; discrimination ability, and a neutron detector using the neutron scintillator are provided. [Means to Solve the Problems] A neutron scintillator comprising a eutectic body composed of laminar lithium fluoride crystals and laminar calcium fluoride crystals alternately arranged in layers, the thickness of the lithium fluoride crystal layers in the eutectic body being 0.1 to 5 &#x3bc;m; or a neutron scintillator comprising a eutectic body composed of laminar lithium fluoride crystals and laminar calcium fluoride crystals alternately arranged in layers, the calcium fluoride crystal layers in the eutectic body being linearly continuous in at least one direction; and a neutron detector basically constructed from any of the neutron scintillators and a photodetector.

A scintillator for neutron detection, comprising a metal fluoride crystal containing, as constituent elements, a metal having a valence of 2 or higher, such as calcium, aluminum or yttrium; lithium; and fluorine, the metal fluoride crystal containing 1.1 to 20 atoms per unit volume (atoms/nm) ofLi, having an effective atomic number of 10 to 40, containing a lanthanoid such as cerium, praseodymium or europium, and being represented by, for instance, LiCaAlF, LiSrAlFand LiYF. The scintillator for neutron detection has high sensitivity to neutron rays, and is reduced in a background noise attributed to &#x3b3; rays.

Scintillator for neutron detection and neutron detector

An easily dispersible cake of precipitated silica, wherein the precipitated silica has a BET specific surface area of at least 220 m/g. When the cake is dispersed in ion-exchange water to provide an aqueous dispersion of the silica of 5% by weight in concentration and further diluted to reduce the silica concentration to 1.5% by weight, the dispersion has a light-scattering index (n-value) of at least 2. The easily dispersible cake can be obtained by simultaneously adding an alkali silicate and a mineral acid to a reaction liquid whose pH is being maintained at a fixed value within a range of 7.5-11.5 and whose temperature is being maintained at 92-98&#xb0; C., thus forming precipitated silica through their reaction, and separating the precipitated silica from the reaction liquid in wet state.

Growing community of inventors

Shunan, Japan

Kentaro Fukuda